So far we've seen how to link a static URL to a Blazor component. Static URLs are only useful for static content, if we want the same component to render different views based on information in the URL (such as a customer ID) then we need to use route parameters.
A route parameter is defined in the URL by wrapping its name in a pair of {
braces }
when adding a component's
@page
declaration.
@page "/customer/{CustomerId}
Capturing a parameter value
Capturing the value of a parameter is as simple as adding a property with the same name and decorating it with a
[Parameter]
attribute.
@page "/"
@page "/customer/{CustomerId}"
<h1>
Customer:
@if (string.IsNullOrEmpty(CustomerId))
{
@:None
}
else
{
@CustomerId
}
</h1>
<h3>Select a customer</h3>
<ul>
<li><a href="/customer/Microsoft">Microsoft</a></li>
<li><a href="/customer/Google">Google</a></li>
<li><a href="/customer/IBM">IBM</a></li>
</ul>
@code {
[Parameter]
public string CustomerId { get; set; }
}
Note that when a navigation is made to a new URL that resolves to the same type of component as the current page,
the component will not be destroyed before navigation and the OnInitialized*
lifecycle methods will not be executed.
The navigation is simply seen as a change to the component's parameters.